Nanoplatelets assembled CuCo2S4/N doped rGO nanocomposites for hydrogen evolution reaction

Designing a commercial and stable electrocatalysts is a crucial factor for hydrogen evolution reaction (HER) to replace noble electrocatalysts. In particular, thiospinel-structured metal sulfide is explored in wide areas like supercapacitors, lithium-ion, HER, and oxygen reduction reactions (ORR) because of distinctive features and interesting magnetic and electrical properties. The present work revealed the preparation of CuCo2S4 with N doped different amounts of rGO by a hydrothermal process and the electrocatalysts used for HER. The present study aims to influence morphological and electrocatalytic action of CuCo2S4 by optimizing amount of rGO content and accelerate electron transfer rate and offer rich active sites. Strong interaction between CuCo2S4 with N-rGO were examined with the help of physico-chemical property analysis such as diffraction, microscopic and spectroscopic studies, which confirming the formation of nanocomposite material. The morphological studies confirmed the formation of nanoplatelets assembled CuCo2S4 structure with the N doped rGO sheets and the elemental analysis has also confirmed the uniform distribution of the following elements such as copper (Cu), cobalt (Co), sulfur (S), nitrogen (N) and carbon (C). Among all the prepared materials, the electrocatalyst of CuCo2S4/N-rGO-50 yield promising electrocatalytic activity when compared to different amount of rGO. CuCo2S4/N-rGO-50 requires 86 mV overpotential to deliver 10 mA/cm2, likewise Tafel slope of nanomaterial was 95 mV/dec, respectively. Moreover, electrocatalyst exhibited excellent double-layer capacitance (Cdl) value, small charge-transfer resistance of 8.60 mF/cm2, 3.55 Ω and high stability with the minimal loss over 24 h. Therefore, these findings may open way to explore thiospinel-structured metal sulfide with carbon composites for optimized H2 evolution reaction.